The Colorado River forms the border between California and Arizona.
California is on Arizona's eastern border
Both Nevada and Arizona border California. Utah and Ohio do not border California.
California
Oregon, Nevada, Arizona
Arizona
New Mexico, Colorado, Utah, Nevada and California all border Arizona.
Oregon and Arizona border California and Nevada. Salem is the capital city in the U.S. state of Oregon. Phoenix is the capital city in the U.S. state of Arizona.
Arizona and California is bordered by the state of Nevada. California and Arizona are also bordered by the country of Mexico.
No state borders California to the west. Hawaii is the only state west(ish) of California but they do not share a border.
California.
Texas, New Mexico, Arizona and California
The Colorado River.